Toilet discharge vented Loop?

[SKYCHENEY]

Okay, this weekend I removed one of the three GalleyMaid Delta toilets. Not to big of a job, but now I'm ready to start on installing the new Raritan Atlantes. In the manual, it says to retain water in the bowl, you must install a vented loop in the discharge line. I understand that to mean that I need to run the line up higher than the bowl and at it's peak, tee off a vent line. Since the GM did not have this vent, I will now have to add it. My question is, should I tie this vent into the existing tank vent or put a new vent through the hull? I think that a vent line should not have any low spots that could retain liquid, so the most direct run to outside may be best. But, I really don't want to drill through the hull if I can help it. Also, the master head is an aweful long way from the tank vent. Thoughts? Experiences?

 

[Trojan]

You can T off any vent line you have on the holding tank. It's a very small line it's only a vacuum breaker .Bill

 

[Ross Macdonald]

I did this a year ago. Took out 3 Galley Maid heads and replaced with Atlantes heads in a 60 Hatt convertible. I purchase the 32 V versions so we could use the same wiring. I just made teak backing plates for the touch pad flush switches which I mounted over the same holes. I'm assuming you are plumbing into the freshwater system for freshwater heads?? We had a real space issue with the vented loops for water retention in the bowls. We ended putting connectors at an acessible place in the discharge lines with duckbill valves and it seems to work. We had to improvise on that part of the install. That may be worth a try as an alternative.

 

[Nonchalant1]

GallyMaid does recommend that exact vent loop, and the design is simple. My 53MY has the vent loops in every head. The head discharge line has an upwards loop (usually like a sink trap mounted upside down). You just create the vent loop with a small copper tube tapped into the top of the discharge loop which runs back up to a tee in the bowl water inlet pipe at the top of the bowl. Since there's no water flowing through the inlet pipe after the flush is complete, air can travel to the discharge loop to break the vacuum and water is retained in the bowl at the height of the discharge loop. Be careful not to have the discharge loop too high or you'll have too much water in the bowl. The height of the discharge loop determines how high the water is left in the bowl.

Doug Shuman

 

[SKYCHENEY]

Doug,
Yes, I had the loops that you are talking about on the old GM's, but the Atlantes is a different animal. According to Raritan, I must have a vented loop somewhere in the discharge line higher than the bowl, but I don't think that it determines the level in the bowl. It just breaks the vacuum to keep the bowl water from siphoning out into the tank. There must be some sort of check valve in toilet itself to prevent backflow into the bowl.

Ross,
I thought about a duckbill valve to avoid running all the vents, but I am affraid of it releasing odor into the boat. Do you have any problem with that? Yes, they are 32v and freshwater, just like you installed. Any other tips you have from your install would be helpful.

Thanks guys!

 

[wshelton]

FWIW, I have intalled the Atlantes heads in three boats, two of which I did not install a vented loop, but did run the discharge line in a loop fashion above the waterline. The heads all have worked properly and retain appropriate water level in the bowl.

 

[Ross Macdonald]

I haven't had any problems with the duck bill valve set up with odors. We are on the boat 4 nites out of every week and I try to flush the fwd head at least once a day just to run it. While the others get regular use, the fwd head isn't used much. I also put a little liquid Joy dish soap in each head and flush it through each week. The previous reply on the loop in the hose itself sounds like it works well too. I used the heavy green striped sanitation hose and it was really tough to get much of a bend in it. Hope it all works out. Knock on wood, but the heads have been great since we did this 1 1/2 years ago.

 

[SKYCHENEY]

Thanks for the info. I think I will install the loop without a vent and then if I need it, all I have to do is remove the cap from the top of the loop and attach a vent hose to it. wshelton, if it works okay that way for you, maybe I can get by without all that extra work of running 3 vents.